<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<style>
    * {
        margin: 0;
        padding: 0;
    }

    .box {
        width: 100%;
        height: 200px;
        border: 1px solid black;
        border-radius: 20px;
    }

    .box1 {
        width: 70%;
        height: 50%;
        margin: 40px auto;
    }

    .box p {
        font-size: 25px;
        text-align: center;
    }

    table {
        border-collapse: collapse;
        position: relative;
        margin: 0 auto;
        width: 70%;
        height: 60%;
    }

    table td {
        font-size: 40px;
        text-align: center;
        color: aqua;
    }

    table td:hover {
        cursor: pointer;
    }

    table .w:hover::after {
        content: attr(ww);
        display: inline-block;
        width: 96px;
        height: 45px;
        padding: 10px;
        background-color: rgb(64, 63, 64);
        color: white;
        position: absolute;
        left: 36px;
        bottom: 55px;
    }

    table .h:hover::after {
        content: attr(hh);
        display: inline-block;
        width: 124px;
        height: 45px;
        padding: 10px;
        background-color: rgb(64, 63, 64);
        color: white;
        position: absolute;
        left: 226px;
        bottom: 55px;
    }

    table .c:hover::after {
        content: attr(cc);
        display: inline-block;
        width: 96px;
        height: 45px;
        padding: 10px;
        background-color: rgb(64, 63, 64);
        color: white;
        position: absolute;
        left: 427px;
        bottom: 55px;
    }

    table .j:hover::after {
        content: attr(jj);
        display: inline-block;
        width: 196px;
        height: 45px;
        padding: 10px;
        background-color: rgb(64, 63, 64);
        color: white;
        position: absolute;
        left: 645px;
        bottom: 55px;
    }
</style>

<body>
    <div class="box">
        <div class="box1">
            <p>鼠标悬浮在下列的单元格中查看描述</p>
            <table border="1" cellspacing="0">
                <tr>
                    <td class="w" ww="W3C">W3C</td>
                    <td class="h" hh="HTML">HTML</td>
                    <td class="c" cc="CSS">CSS</td>
                    <td class="j" jj="JavaScript">JavaScript</td>
                </tr>
            </table>
        </div>
    </div>

</body>

</html>